Engine driven "motor" vehicles typically am equipped with a battery to supply energy for starting the engine and to supply power for auxiliary electric equipment such as headlights, horn and various instruments. The power for the battery is normally provided by an alternator or a generator which is pulley driven by the crank shaft of the engine. The efficiency of these systems is generally less than about 35 percent.
The gasses exhausted from the engines of motor vehicles is at a relatively high temperature. For Diesel engine trucks the temperatures are in the range of about 850 to 1000 degrees Fahrenheit, much higher than the ambient temperature or the temperature of the engine's cooling water. These gasses normally are exhausted to the atmosphere so that the energy represented by these high temperature exhaust gasses is completely wasted.
Thermoelectric modules are currently available which can produce electric power when a substantial temperature difference is available. Specifically, thermoelectric modules are commercially available having dimensions of 2.1 inches.times.2.1 inches.times.0.2 inch thick which will produce 13 watts when the temperature difference between its hot side and cold side is about 360 degrees Fahrenheit.